I set out trying to create a way to funnel multicast traffic from various back end networks to a remote facility without creating a bunch of very special new interfaces at the remote facility. OTV seems like the perfect technology for this because of they have addressed alot of the problems that normally come with layer 2 overlays. My remote facility might not have multicast available so that meant I needed the OTV unicast transport option. This is also sensitive data so I needed to encrypt the traffic and I might not have jumbo frames available so that meant the only platform that could encrypt and fragment OTV left to me was the ASR or CSR routers. I started with the CSR(virtual) since all of my ASR (physical) were busy.

There is a lot of documentation about how to perform OTV on the Nexus 7000, but much less on the ASR/CSR line.

It was fairly easy to get unicast up and running, I started with this blog which is very well written but contains one mistake from what I can tell I’ll get to that later.

ip igmp snooping querier

It must be on both routers.

I cannot understand why this command is so well hidden, in all of the documentation I could find it is nowhere to be found. I opened a TAC case and the Cisco engineer could not find the answer even with his internal access.